The yearly formation and shrinkage of the Greenland ice sheet is a delicate balancing act, with melting glaciers reducing its mass each summer before the snowfall replenishes it in the winter. New analysis of satellite data has revealed that these opposing forces are no longer working in harmony and the ice sheet is now shrinking so much that, even if climate change were to halt tomorrow, it has already passed a point of no return and would continue to shrink for some time.

The data revealed that throughout the 80s and 90s, the balance between snowfall and ice loss was more or less sustainable, with the sheet shedding about 450 gigatons each year before regaining it through snowfall. However, the team found that around the turn of the century the ice loss started to pick up, with the glaciers losing around 500 gigatons each year while snowfall remained the same.

Graph depicting ice loss in Greenland since 1985

This differential over the past 15 to 20 years has now pushed the ice sheet past the point of no return, according to the scientists. They report that the large glaciers have retreated by an average of 3 km (1.86 mi) since 1985, with many of them now sitting in deep water that makes them more susceptible to melting, only compounding the problem.

Prior to 2000, the team says that the ice sheet had a 50-50 chance of either gaining or losing mass each year. In the current conditions, they expect it to gain mass only once in 100 years. Moreover, the researchers say that even if we were to somehow stop the process of climate change today, ice loss would continue to outstrip ice accumulation each year.

“Glacier retreat has knocked the dynamics of the whole ice sheet into a constant state of loss,” says Ian Howat, a co-author on the paper. “Even if the climate were to stay the same or even get a little colder, the ice sheet would still be losing mass.”

The findings are just the latest in a series of grim observations concerning the ice sheet and rising sea levels, of which Greenland’s melting glaciers are a big contributor. One paper published back in April revealed that the Greenland ice sheet lost 600 gigatons of mass in 2019, the biggest drop since records began in 1948.

https://newatlas.com/environment/melting-greenland-ice-sheet-tipping-point/

PermeateFree said:

The yearly formation and shrinkage of the Greenland ice sheet is a delicate balancing act, with melting glaciers reducing its mass each summer before the snowfall replenishes it in the winter. New analysis of satellite data has revealed that these opposing forces are no longer working in harmony and the ice sheet is now shrinking so much that, even if climate change were to halt tomorrow, it has already passed a point of no return and would continue to shrink for some time.

The data revealed that throughout the 80s and 90s, the balance between snowfall and ice loss was more or less sustainable, with the sheet shedding about 450 gigatons each year before regaining it through snowfall. However, the team found that around the turn of the century the ice loss started to pick up, with the glaciers losing around 500 gigatons each year while snowfall remained the same.

Graph depicting ice loss in Greenland since 1985

This differential over the past 15 to 20 years has now pushed the ice sheet past the point of no return, according to the scientists. They report that the large glaciers have retreated by an average of 3 km (1.86 mi) since 1985, with many of them now sitting in deep water that makes them more susceptible to melting, only compounding the problem.

Prior to 2000, the team says that the ice sheet had a 50-50 chance of either gaining or losing mass each year. In the current conditions, they expect it to gain mass only once in 100 years. Moreover, the researchers say that even if we were to somehow stop the process of climate change today, ice loss would continue to outstrip ice accumulation each year.

“Glacier retreat has knocked the dynamics of the whole ice sheet into a constant state of loss,” says Ian Howat, a co-author on the paper. “Even if the climate were to stay the same or even get a little colder, the ice sheet would still be losing mass.”

The findings are just the latest in a series of grim observations concerning the ice sheet and rising sea levels, of which Greenland’s melting glaciers are a big contributor. One paper published back in April revealed that the Greenland ice sheet lost 600 gigatons of mass in 2019, the biggest drop since records began in 1948.

https://newatlas.com/environment/melting-greenland-ice-sheet-tipping-point/

Doesn’t look too bad to me. June 2020 melting was as low as, or lower than, the melting from all five years from 2012 to 2019.
Sure it’s above the 1981 to 2001 median this year, but only by about 15%.

Source http://nsidc.org/greenland-today/

mollwollfumble said:

PermeateFree said:

The yearly formation and shrinkage of the Greenland ice sheet is a delicate balancing act, with melting glaciers reducing its mass each summer before the snowfall replenishes it in the winter. New analysis of satellite data has revealed that these opposing forces are no longer working in harmony and the ice sheet is now shrinking so much that, even if climate change were to halt tomorrow, it has already passed a point of no return and would continue to shrink for some time.

The data revealed that throughout the 80s and 90s, the balance between snowfall and ice loss was more or less sustainable, with the sheet shedding about 450 gigatons each year before regaining it through snowfall. However, the team found that around the turn of the century the ice loss started to pick up, with the glaciers losing around 500 gigatons each year while snowfall remained the same.

Graph depicting ice loss in Greenland since 1985

This differential over the past 15 to 20 years has now pushed the ice sheet past the point of no return, according to the scientists. They report that the large glaciers have retreated by an average of 3 km (1.86 mi) since 1985, with many of them now sitting in deep water that makes them more susceptible to melting, only compounding the problem.

Prior to 2000, the team says that the ice sheet had a 50-50 chance of either gaining or losing mass each year. In the current conditions, they expect it to gain mass only once in 100 years. Moreover, the researchers say that even if we were to somehow stop the process of climate change today, ice loss would continue to outstrip ice accumulation each year.

“Glacier retreat has knocked the dynamics of the whole ice sheet into a constant state of loss,” says Ian Howat, a co-author on the paper. “Even if the climate were to stay the same or even get a little colder, the ice sheet would still be losing mass.”

The findings are just the latest in a series of grim observations concerning the ice sheet and rising sea levels, of which Greenland’s melting glaciers are a big contributor. One paper published back in April revealed that the Greenland ice sheet lost 600 gigatons of mass in 2019, the biggest drop since records began in 1948.

https://newatlas.com/environment/melting-greenland-ice-sheet-tipping-point/

Doesn’t look too bad to me. June 2020 melting was as low as, or lower than, the melting from all five years from 2012 to 2019.
Sure it’s above the 1981 to 2001 median this year, but only by about 15%.

Source http://nsidc.org/greenland-today/

Thank you again for your opinion, I’m sure it will put many minds at ease.

PermeateFree said:

mollwollfumble said:

PermeateFree said:

The yearly formation and shrinkage of the Greenland ice sheet is a delicate balancing act, with melting glaciers reducing its mass each summer before the snowfall replenishes it in the winter. New analysis of satellite data has revealed that these opposing forces are no longer working in harmony and the ice sheet is now shrinking so much that, even if climate change were to halt tomorrow, it has already passed a point of no return and would continue to shrink for some time.

The data revealed that throughout the 80s and 90s, the balance between snowfall and ice loss was more or less sustainable, with the sheet shedding about 450 gigatons each year before regaining it through snowfall. However, the team found that around the turn of the century the ice loss started to pick up, with the glaciers losing around 500 gigatons each year while snowfall remained the same.

Graph depicting ice loss in Greenland since 1985

This differential over the past 15 to 20 years has now pushed the ice sheet past the point of no return, according to the scientists. They report that the large glaciers have retreated by an average of 3 km (1.86 mi) since 1985, with many of them now sitting in deep water that makes them more susceptible to melting, only compounding the problem.

Prior to 2000, the team says that the ice sheet had a 50-50 chance of either gaining or losing mass each year. In the current conditions, they expect it to gain mass only once in 100 years. Moreover, the researchers say that even if we were to somehow stop the process of climate change today, ice loss would continue to outstrip ice accumulation each year.

“Glacier retreat has knocked the dynamics of the whole ice sheet into a constant state of loss,” says Ian Howat, a co-author on the paper. “Even if the climate were to stay the same or even get a little colder, the ice sheet would still be losing mass.”

The findings are just the latest in a series of grim observations concerning the ice sheet and rising sea levels, of which Greenland’s melting glaciers are a big contributor. One paper published back in April revealed that the Greenland ice sheet lost 600 gigatons of mass in 2019, the biggest drop since records began in 1948.

https://newatlas.com/environment/melting-greenland-ice-sheet-tipping-point/

Doesn’t look too bad to me. June 2020 melting was as low as, or lower than, the melting from all five years from 2012 to 2019.
Sure it’s above the 1981 to 2001 median this year, but only by about 15%.

Source http://nsidc.org/greenland-today/

Thank you again for your opinion, I’m sure it will put many minds at ease.

You might also like to read the original paper: “Dynamic ice loss from the Greenland Ice Sheet driven by sustained glacier retreat” Published: 13 August 2020. It has a list of references also available for your consideration.

https://www.nature.com/articles/s43247-020-0001-2

PermeateFree said:

You might also like to read the original paper: “Dynamic ice loss from the Greenland Ice Sheet driven by sustained glacier retreat” Published: 13 August 2020. It has a list of references also available for your consideration.

https://www.nature.com/articles/s43247-020-0001-2

Ta. Reading it now.

“Dynamic ice loss from the Greenland Ice Sheet driven by sustained glacier retreat”.

> The Greenland Ice Sheet (is) the largest single contributor to rising sea levels

Thank you. I’ve suspected as much. I never trusted the theory that thermal expansion of seawater causes more rise in sea levels than continental ice sheet melting.

> We compare decadal variability in discharge and calving front position and find that increased glacier discharge was due almost entirely to the retreat of glacier fronts, rather than inland ice sheet processes.

That’s a relief. If inland ice sheet thinning was the primary cause then we would be in trouble.

> Rates of Greenland glacier retreat have accelerated

Well, obviously, the world is warming.

> We find that discharge is now ~14% greater than the rate observed during 1985–1999.

:-) That’s exactly in agreement with what I said above, “it’s above the 1981 to 2001 median this year, but only by about 15%”

mollwollfumble said:

PermeateFree said:

You might also like to read the original paper: “Dynamic ice loss from the Greenland Ice Sheet driven by sustained glacier retreat” Published: 13 August 2020. It has a list of references also available for your consideration.

https://www.nature.com/articles/s43247-020-0001-2

Ta. Reading it now.

“Dynamic ice loss from the Greenland Ice Sheet driven by sustained glacier retreat”.

> The Greenland Ice Sheet (is) the largest single contributor to rising sea levels

Thank you. I’ve suspected as much. I never trusted the theory that thermal expansion of seawater causes more rise in sea levels than continental ice sheet melting.

> We compare decadal variability in discharge and calving front position and find that increased glacier discharge was due almost entirely to the retreat of glacier fronts, rather than inland ice sheet processes.

That’s a relief. If inland ice sheet thinning was the primary cause then we would be in trouble.

> Rates of Greenland glacier retreat have accelerated

Well, obviously, the world is warming.

> We find that discharge is now ~14% greater than the rate observed during 1985–1999.

:-) That’s exactly in agreement with what I said above, “it’s above the 1981 to 2001 median this year, but only by about 15%”

LOL

All-time record melt: Greenland loses 532 billion tonnes of ice
By Seth Borenstein

Washington: Greenland lost a record amount of ice during an extra warm 2019, adding more than 532 trillion litres of water to already rising sea levels.

After two years when summer ice melt had been minimal, last summer shattered all records with 532 billion metric tonnes of ice melting, according to satellite measurements reported in a new study.

Read more

http://www.theage.com.au/world/europe/all-time-record-melt-greenland-loses-532-billion-tonnes-of-ice-20200821-p55o28.html

I sometimes forget that the Age (SMH) exists. Then Witty reminds me :)

sibeen said:

I sometimes forget that the Age (SMH) exists. Then Witty reminds me :)

I try my best.

The Greenland ice sheet has melted past the point of no return
Even if global warming stopped today, the ice would keep shrinking

Graphic detail
Aug 25th 2020

ANNUAL SNOWFALL can no longer replenish the melted ice that flows into the ocean from Greenland’s glaciers. That is the conclusion of a new analysis of almost 40 years’ satellite data by researchers at Ohio State University. The ice loss, they think, is now so great that it has triggered an irreversible feedback loop: the sheet will keep melting, even if all climate-warming emissions are miraculously curtailed. This is bad news for coastal cities, given that Greenland boasts the largest ice sheet on the planet after Antarctica. Since 2000 its melting ice has contributed about a millimetre a year to rising sea levels. The loss of the entire ice sheet would raise them by more than seven metres, enough to reconfigure the majority of the world’s coastlines.

In the 1980s and 1990s, Greenland’s ice maintained a rough equilibrium. Each year the sheet lost some 400bn tonnes of ice in the summer—both by ice and snow melting on the surface, and the “discharge” of ice by glaciers losing chunks as they push out into the sea. This was replenished by a similar amount of fresh snow in the winter. But after 2000 the ice sheet began losing mass permanently. The amount that has disappeared is so huge that it has caused a noticeable change in the gravitational field over the island. It has also caused the glaciers to retreat by about 3km since 1985, exposing more of them to warmer ocean water. This has increased the rate of melting to the point where, even if the climate stopped getting hotter, more ice would be discharged each year than could be replaced, the scientists reckon. “The ice sheet is now in this new dynamic state, where even if we went back to a climate that was more like what we had 20 or 30 years ago, we would still be pretty quickly losing mass,” explains Ian Howar, one of the study’s authors.

Over the past three decades, the Arctic has warmed at least twice as fast as the rest of the world. This is because of a phenomenon known as Arctic amplification, in which higher concentrations of greenhouse gases produce larger increases in temperature at high latitudes. It also means that changes in the Arctic region are an important indicator of the progression and impacts of climate change. The decline of the Greenland ice sheet is a harbinger of things to come. “Greenland is going to be the canary in the coal mine,” says Mr Howar. “And the canary is pretty much dead at this point.”

https://www.economist.com/graphic-detail/2020/08/25/the-greenland-ice-sheet-has-melted-past-the-point-of-no-return?